在画布中随机位置产卵图像

Question

我有 canvas and a panel 。我想 Spawn 不同的图像UI对象在我的面板内的随机位置（在屏幕上）。我采用了面板的x和y min和最大限制，以生成一个随机位置（使用这些限制），但问题是对象不是在所需位置实例化。这是我的代码。

public class ImageSpawnerScreen : MonoBehaviour {
    public float waitTime = 2;
    public float cubeSpawnTotal = 10;
    public List<GameObject> cubePrefabList;
    float xPosMinLimit = -347;
    float xPosMaxLimit = 340;
    float yPosMinLimit = -458f;
    float yPosMaxLimit = 450f;
    public GameObject panel;
    void Start()
    {
        StartCoroutine(SpawnCube());
    }

    IEnumerator SpawnCube()
    {
        for (int i = 0; i < cubeSpawnTotal; i++)
        {
            GameObject prefabToSpawn = cubePrefabList[Random.Range(0, cubePrefabList.Count - 1)];
            //Vector3 spawnPosition = Camera.main.ScreenToViewportPoint(new Vector3(Random.Range(0,Screen.width),0,Random.Range(0,Screen.height)));  //Random.Range(xPosMinLimit, xPosMaxLimit);
            float xPos = Random.Range(xPosMinLimit, xPosMaxLimit);
            float yPos = Random.Range(yPosMinLimit, yPosMaxLimit);
            Vector3 spawnPosition = new Vector3(xPos, yPos, 0f);
            GameObject spwanObj = Instantiate(prefabToSpawn, spawnPosition, Quaternion.identity) as GameObject;
            spwanObj.transform.parent = panel.transform;
            spwanObj.transform.position = spawnPosition;
            yield return new WaitForSeconds(waitTime);
        }
    }
}

我检查了实例化对象位置远离给定的随机范围位置。我做错了什么？我认为它是 rect Transform ，因此我必须以不同的方式设置其位置。

Answer 1

确实，您需要在Canvas内使用RectTransform。您也不需要-1为您的List.Count。在下面的评论中检查链接。

我认为以下脚本将执行您正在寻找的事情：

public class ImageSpawnerScreen : MonoBehaviour
{
    public float waitTime = 2;
    public float cubeSpawnTotal = 10;
    public List<GameObject> imagesList;
    public RectTransform panel;
    void Start()
    {
        StartCoroutine(SpawnImage());
    }

    IEnumerator SpawnImage()
    {
        for (int i = 0; i < cubeSpawnTotal; i++)
        {
            GameObject imageToSpawn = imagesList[Random.Range(0, imagesList.Count)]; // Remove -1 after count since is exclusive for int (https://docs.unity3d.com/ScriptReference/Random.Range.html)
            Vector3 spawnPosition = GetBottomLeftCorner(panel) - new Vector3(Random.Range(0, panel.rect.x), Random.Range(0, panel.rect.y), 0);
            print("Spawn image at position: " + spawnPosition);
            GameObject spwanObj = Instantiate(imageToSpawn, spawnPosition, Quaternion.identity, panel);
            yield return new WaitForSeconds(waitTime);
        }
    }
    Vector3 GetBottomLeftCorner(RectTransform rt)
    {
        Vector3[] v = new Vector3[4];
        rt.GetWorldCorners(v);
        return v[0];
    }
}

让我知道您是否需要更多解释。

Answer 2

要管理帆布对象的位置，您应该绝对使用RectTransform而不是常规transform。在您的情况下，您必须做类似：

的事情

m_RectTransform = GetComponent<RectTransform>();

对于设置位置 - 在画布内部的对象上看到的坐标不是.position，而是RectTransform.anchoredPosition，因此您应该在代码中使用它。这是anchoredPosition的官方文档。

Answer 3

public class ImageSpawnerScreen : MonoBehaviour {
    public float waitTime = 2;
    public float cubeSpawnTotal = 10;
    public List<GameObject> cubePrefabList;
    public GameObject panel;
    void Start()
    {
        StartCoroutine(SpawnCube());
    }

    IEnumerator SpawnCube()
    {
        for (int i = 0; i < cubeSpawnTotal; i++)
        {
            GameObject prefabToSpawn = cubePrefabList[Random.Range(0, cubePrefabList.Count - 1)];
            //Vector3 spawnPosition = Camera.main.ScreenToViewportPoint(new Vector3(Random.Range(0,Screen.width),0,Random.Range(0,Screen.height)));  //Random.Range(xPosMinLimit, xPosMaxLimit);
            float xPos = Random.Range(0, Screen.width);
            float yPos = Random.Range(0, Screen.height);
            Vector3 spawnPosition = new Vector3(xPos, yPos, 0f);
            GameObject spwanObj = Instantiate(prefabToSpawn, spawnPosition, Quaternion.identity) as GameObject;
            spwanObj.transform.parent = panel.transform;
            spwanObj.transform.position = spawnPosition;
            yield return new WaitForSeconds(waitTime);
        }
    }
}

这应该帮助您。